/*
 * Originally from Linux v4.9
 * Paul Mackerras       August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 *
 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *   {engebret|bergner}@us.ibm.com
 *
 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
 *
 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
 * Grant Likely.
 *
 * Modified for U-Boot
 * Copyright (c) 2017 Google, Inc
 *
 * This file follows drivers/of/base.c with functions in the same order as the
 * Linux version.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <libfdt.h>
#include <dm/of_access.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/ioport.h>

DECLARE_GLOBAL_DATA_PTR;

/* list of struct alias_prop aliases */
LIST_HEAD(aliases_lookup);

/* "/aliaes" node */
static struct device_node *of_aliases;

/* "/chosen" node */
static struct device_node *of_chosen;

/* node pointed to by the stdout-path alias */
static struct device_node *of_stdout;

/* pointer to options given after the alias (separated by :) or NULL if none */
static const char *of_stdout_options;

/**
 * struct alias_prop - Alias property in 'aliases' node
 *
 * The structure represents one alias property of 'aliases' node as
 * an entry in aliases_lookup list.
 *
 * @link:       List node to link the structure in aliases_lookup list
 * @alias:      Alias property name
 * @np:         Pointer to device_node that the alias stands for
 * @id:         Index value from end of alias name
 * @stem:       Alias string without the index
 */
struct alias_prop {
        struct list_head link;
        const char *alias;
        struct device_node *np;
        int id;
        char stem[0];
};

int of_n_addr_cells(const struct device_node *np)
{
        const __be32 *ip;

        do {
                if (np->parent)
                        np = np->parent;
                ip = of_get_property(np, "#address-cells", NULL);
                if (ip)
                        return be32_to_cpup(ip);
        } while (np->parent);

        /* No #address-cells property for the root node */
        return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
}

int of_n_size_cells(const struct device_node *np)
{
        const __be32 *ip;

        do {
                if (np->parent)
                        np = np->parent;
                ip = of_get_property(np, "#size-cells", NULL);
                if (ip)
                        return be32_to_cpup(ip);
        } while (np->parent);

        /* No #size-cells property for the root node */
        return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
}

int of_simple_addr_cells(const struct device_node *np)
{
        const __be32 *ip;

        ip = of_get_property(np, "#address-cells", NULL);
        if (ip)
                return be32_to_cpup(ip);

        /* Return a default of 2 to match fdt_address_cells()*/
        return 2;
}

int of_simple_size_cells(const struct device_node *np)
{
        const __be32 *ip;

        ip = of_get_property(np, "#size-cells", NULL);
        if (ip)
                return be32_to_cpup(ip);

        /* Return a default of 2 to match fdt_size_cells()*/
        return 2;
}

struct property *of_find_property(const struct device_node *np,
                                  const char *name, int *lenp)
{
        struct property *pp;

        if (!np)
                return NULL;

        for (pp = np->properties; pp; pp = pp->next) {
                if (strcmp(pp->name, name) == 0) {
                        if (lenp)
                                *lenp = pp->length;
                        break;
                }
        }
        if (!pp && lenp)
                *lenp = -FDT_ERR_NOTFOUND;

        return pp;
}

struct device_node *of_find_all_nodes(struct device_node *prev)
{
        struct device_node *np;

        if (!prev) {
                np = gd->of_root;
        } else if (prev->child) {
                np = prev->child;
        } else {
                /*
                 * Walk back up looking for a sibling, or the end of the
                 * structure
                 */
                np = prev;
                while (np->parent && !np->sibling)
                        np = np->parent;
                np = np->sibling; /* Might be null at the end of the tree */
        }

        return np;
}

const void *of_get_property(const struct device_node *np, const char *name,
                            int *lenp)
{
        struct property *pp = of_find_property(np, name, lenp);

        return pp ? pp->value : NULL;
}

static const char *of_prop_next_string(struct property *prop, const char *cur)
{
        const void *curv = cur;

        if (!prop)
                return NULL;

        if (!cur)
                return prop->value;

        curv += strlen(cur) + 1;
        if (curv >= prop->value + prop->length)
                return NULL;

        return curv;
}

int of_device_is_compatible(const struct device_node *device,
                            const char *compat, const char *type,
                            const char *name)
{
        struct property *prop;
        const char *cp;
        int index = 0, score = 0;

        /* Compatible match has highest priority */
        if (compat && compat[0]) {
                prop = of_find_property(device, "compatible", NULL);
                for (cp = of_prop_next_string(prop, NULL); cp;
                     cp = of_prop_next_string(prop, cp), index++) {
                        if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
                                score = INT_MAX/2 - (index << 2);
                                break;
                        }
                }
                if (!score)
                        return 0;
        }

        /* Matching type is better than matching name */
        if (type && type[0]) {
                if (!device->type || of_node_cmp(type, device->type))
                        return 0;
                score += 2;
        }

        /* Matching name is a bit better than not */
        if (name && name[0]) {
                if (!device->name || of_node_cmp(name, device->name))
                        return 0;
                score++;
        }

        return score;
}

bool of_device_is_available(const struct device_node *device)
{
        const char *status;
        int statlen;

        if (!device)
                return false;

        status = of_get_property(device, "status", &statlen);
        if (status == NULL)
                return true;

        if (statlen > 0) {
                if (!strcmp(status, "okay"))
                        return true;
        }

        return false;
}

struct device_node *of_get_parent(const struct device_node *node)
{
        const struct device_node *np;

        if (!node)
                return NULL;

        np = of_node_get(node->parent);

        return (struct device_node *)np;
}

static struct device_node *__of_get_next_child(const struct device_node *node,
                                               struct device_node *prev)
{
        struct device_node *next;

        if (!node)
                return NULL;

        next = prev ? prev->sibling : node->child;
        /*
         * coverity[dead_error_line : FALSE]
         * Dead code here since our current implementation of of_node_get()
         * always returns NULL (Coverity CID 163245). But we leave it as is
         * since we may want to implement get/put later.
         */
        for (; next; next = next->sibling)
                if (of_node_get(next))
                        break;
        of_node_put(prev);
        return next;
}

#define __for_each_child_of_node(parent, child) \
        for (child = __of_get_next_child(parent, NULL); child != NULL; \
             child = __of_get_next_child(parent, child))

static struct device_node *__of_find_node_by_path(struct device_node *parent,
                                                  const char *path)
{
        struct device_node *child;
        int len;

        len = strcspn(path, "/:");
        if (!len)
                return NULL;

        __for_each_child_of_node(parent, child) {
                const char *name = strrchr(child->full_name, '/');

                name++;
                if (strncmp(path, name, len) == 0 && (strlen(name) == len))
                        return child;
        }
        return NULL;
}

#define for_each_property_of_node(dn, pp) \
        for (pp = dn->properties; pp != NULL; pp = pp->next)

struct device_node *of_find_node_opts_by_path(const char *path,
                                              const char **opts)
{
        struct device_node *np = NULL;
        struct property *pp;
        const char *separator = strchr(path, ':');

        if (opts)
                *opts = separator ? separator + 1 : NULL;

        if (strcmp(path, "/") == 0)
                return of_node_get(gd->of_root);

        /* The path could begin with an alias */
        if (*path != '/') {
                int len;
                const char *p = separator;

                if (!p)
                        p = strchrnul(path, '/');
                len = p - path;

                /* of_aliases must not be NULL */
                if (!of_aliases)
                        return NULL;

                for_each_property_of_node(of_aliases, pp) {
                        if (strlen(pp->name) == len && !strncmp(pp->name, path,
                                                                len)) {
                                np = of_find_node_by_path(pp->value);
                                break;
                        }
                }
                if (!np)
                        return NULL;
                path = p;
        }

        /* Step down the tree matching path components */
        if (!np)
                np = of_node_get(gd->of_root);
        while (np && *path == '/') {
                struct device_node *tmp = np;

                path++; /* Increment past '/' delimiter */
                np = __of_find_node_by_path(np, path);
                of_node_put(tmp);
                path = strchrnul(path, '/');
                if (separator && separator < path)
                        break;
        }

        return np;
}

struct device_node *of_find_compatible_node(struct device_node *from,
                const char *type, const char *compatible)
{
        struct device_node *np;

        for_each_of_allnodes_from(from, np)
                if (of_device_is_compatible(np, compatible, type, NULL) &&
                    of_node_get(np))
                        break;
        of_node_put(from);

        return np;
}

struct device_node *of_find_node_by_phandle(phandle handle)
{
        struct device_node *np;

        if (!handle)
                return NULL;

        for_each_of_allnodes(np)
                if (np->phandle == handle)
                        break;
        (void)of_node_get(np);

        return np;
}

/**
 * of_find_property_value_of_size() - find property of given size
 *
 * Search for a property in a device node and validate the requested size.
 *
 * @np:         device node from which the property value is to be read.
 * @propname:   name of the property to be searched.
 * @len:        requested length of property value
 *
 * @return the property value on success, -EINVAL if the property does not
 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 */
static void *of_find_property_value_of_size(const struct device_node *np,
                                            const char *propname, u32 len)
{
        struct property *prop = of_find_property(np, propname, NULL);

        if (!prop)
                return ERR_PTR(-EINVAL);
        if (!prop->value)
                return ERR_PTR(-ENODATA);
        if (len > prop->length)
                return ERR_PTR(-EOVERFLOW);

        return prop->value;
}

int of_read_u32(const struct device_node *np, const char *propname, u32 *outp)
{
        const __be32 *val;

        debug("%s: %s: ", __func__, propname);
        if (!np)
                return -EINVAL;
        val = of_find_property_value_of_size(np, propname, sizeof(*outp));
        if (IS_ERR(val)) {
                debug("(not found)\n");
                return PTR_ERR(val);
        }

        *outp = be32_to_cpup(val);
        debug("%#x (%d)\n", *outp, *outp);

        return 0;
}

int of_read_u32_array(const struct device_node *np, const char *propname,
                      u32 *out_values, size_t sz)
{
        const __be32 *val;

        debug("%s: %s: ", __func__, propname);
        val = of_find_property_value_of_size(np, propname,
                                             sz * sizeof(*out_values));

        if (IS_ERR(val))
                return PTR_ERR(val);

        debug("size %zd\n", sz);
        while (sz--)
                *out_values++ = be32_to_cpup(val++);

        return 0;
}

int of_property_match_string(const struct device_node *np, const char *propname,
                             const char *string)
{
        const struct property *prop = of_find_property(np, propname, NULL);
        size_t l;
        int i;
        const char *p, *end;

        if (!prop)
                return -EINVAL;
        if (!prop->value)
                return -ENODATA;

        p = prop->value;
        end = p + prop->length;

        for (i = 0; p < end; i++, p += l) {
                l = strnlen(p, end - p) + 1;
                if (p + l > end)
                        return -EILSEQ;
                debug("comparing %s with %s\n", string, p);
                if (strcmp(string, p) == 0)
                        return i; /* Found it; return index */
        }
        return -ENODATA;
}

/**
 * of_property_read_string_helper() - Utility helper for parsing string properties
 * @np:         device node from which the property value is to be read.
 * @propname:   name of the property to be searched.
 * @out_strs:   output array of string pointers.
 * @sz:         number of array elements to read.
 * @skip:       Number of strings to skip over at beginning of list.
 *
 * Don't call this function directly. It is a utility helper for the
 * of_property_read_string*() family of functions.
 */
int of_property_read_string_helper(const struct device_node *np,
                                   const char *propname, const char **out_strs,
                                   size_t sz, int skip)
{
        const struct property *prop = of_find_property(np, propname, NULL);
        int l = 0, i = 0;
        const char *p, *end;

        if (!prop)
                return -EINVAL;
        if (!prop->value)
                return -ENODATA;
        p = prop->value;
        end = p + prop->length;

        for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
                l = strnlen(p, end - p) + 1;
                if (p + l > end)
                        return -EILSEQ;
                if (out_strs && i >= skip)
                        *out_strs++ = p;
        }
        i -= skip;
        return i <= 0 ? -ENODATA : i;
}

static int __of_parse_phandle_with_args(const struct device_node *np,
                                        const char *list_name,
                                        const char *cells_name,
                                        int cell_count, int index,
                                        struct of_phandle_args *out_args)
{
        const __be32 *list, *list_end;
        int rc = 0, cur_index = 0;
        uint32_t count = 0;
        struct device_node *node = NULL;
        phandle phandle;
        int size;

        /* Retrieve the phandle list property */
        list = of_get_property(np, list_name, &size);
        if (!list)
                return -ENOENT;
        list_end = list + size / sizeof(*list);

        /* Loop over the phandles until all the requested entry is found */
        while (list < list_end) {
                rc = -EINVAL;
                count = 0;

                /*
                 * If phandle is 0, then it is an empty entry with no
                 * arguments.  Skip forward to the next entry.
                 */
                phandle = be32_to_cpup(list++);
                if (phandle) {
                        /*
                         * Find the provider node and parse the #*-cells
                         * property to determine the argument length.
                         *
                         * This is not needed if the cell count is hard-coded
                         * (i.e. cells_name not set, but cell_count is set),
                         * except when we're going to return the found node
                         * below.
                         */
                        if (cells_name || cur_index == index) {
                                node = of_find_node_by_phandle(phandle);
                                if (!node) {
                                        debug("%s: could not find phandle\n",
                                              np->full_name);
                                        goto err;
                                }
                        }

                        if (cells_name) {
                                if (of_read_u32(node, cells_name, &count)) {
                                        debug("%s: could not get %s for %s\n",
                                              np->full_name, cells_name,
                                              node->full_name);
                                        goto err;
                                }
                        } else {
                                count = cell_count;
                        }

                        /*
                         * Make sure that the arguments actually fit in the
                         * remaining property data length
                         */
                        if (list + count > list_end) {
                                debug("%s: arguments longer than property\n",
                                      np->full_name);
                                goto err;
                        }
                }

                /*
                 * All of the error cases above bail out of the loop, so at
                 * this point, the parsing is successful. If the requested
                 * index matches, then fill the out_args structure and return,
                 * or return -ENOENT for an empty entry.
                 */
                rc = -ENOENT;
                if (cur_index == index) {
                        if (!phandle)
                                goto err;

                        if (out_args) {
                                int i;
                                if (WARN_ON(count > OF_MAX_PHANDLE_ARGS))
                                        count = OF_MAX_PHANDLE_ARGS;
                                out_args->np = node;
                                out_args->args_count = count;
                                for (i = 0; i < count; i++)
                                        out_args->args[i] =
                                                        be32_to_cpup(list++);
                        } else {
                                of_node_put(node);
                        }

                        /* Found it! return success */
                        return 0;
                }

                of_node_put(node);
                node = NULL;
                list += count;
                cur_index++;
        }

        /*
         * Unlock node before returning result; will be one of:
         * -ENOENT : index is for empty phandle
         * -EINVAL : parsing error on data
         * [1..n]  : Number of phandle (count mode; when index = -1)
         */
        rc = index < 0 ? cur_index : -ENOENT;
 err:
        if (node)
                of_node_put(node);
        return rc;
}

struct device_node *of_parse_phandle(const struct device_node *np,
                                     const char *phandle_name, int index)
{
        struct of_phandle_args args;

        if (index < 0)
                return NULL;

        if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0, index,
                                         &args))
                return NULL;

        return args.np;
}

int of_parse_phandle_with_args(const struct device_node *np,
                               const char *list_name, const char *cells_name,
                               int index, struct of_phandle_args *out_args)
{
        if (index < 0)
                return -EINVAL;

        return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
                                            index, out_args);
}

int of_count_phandle_with_args(const struct device_node *np,
                               const char *list_name, const char *cells_name)
{
        return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
                                            -1, NULL);
}

static void of_alias_add(struct alias_prop *ap, struct device_node *np,
                         int id, const char *stem, int stem_len)
{
        ap->np = np;
        ap->id = id;
        strncpy(ap->stem, stem, stem_len);
        ap->stem[stem_len] = 0;
        list_add_tail(&ap->link, &aliases_lookup);
        debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
              ap->alias, ap->stem, ap->id, of_node_full_name(np));
}

int of_alias_scan(void)
{
        struct property *pp;

        of_aliases = of_find_node_by_path("/aliases");
        of_chosen = of_find_node_by_path("/chosen");
        if (of_chosen == NULL)
                of_chosen = of_find_node_by_path("/chosen@0");

        if (of_chosen) {
                const char *name;

                name = of_get_property(of_chosen, "stdout-path", NULL);
                if (name)
                        of_stdout = of_find_node_opts_by_path(name,
                                                        &of_stdout_options);
        }

        if (!of_aliases)
                return 0;

        for_each_property_of_node(of_aliases, pp) {
                const char *start = pp->name;
                const char *end = start + strlen(start);
                struct device_node *np;
                struct alias_prop *ap;
                ulong id;
                int len;

                /* Skip those we do not want to proceed */
                if (!strcmp(pp->name, "name") ||
                    !strcmp(pp->name, "phandle") ||
                    !strcmp(pp->name, "linux,phandle"))
                        continue;

                np = of_find_node_by_path(pp->value);
                if (!np)
                        continue;

                /*
                 * walk the alias backwards to extract the id and work out
                 * the 'stem' string
                 */
                while (isdigit(*(end-1)) && end > start)
                        end--;
                len = end - start;

                if (strict_strtoul(end, 10, &id) < 0)
                        continue;

                /* Allocate an alias_prop with enough space for the stem */
                ap = malloc(sizeof(*ap) + len + 1);
                if (!ap)
                        return -ENOMEM;
                memset(ap, 0, sizeof(*ap) + len + 1);
                ap->alias = start;
                of_alias_add(ap, np, id, start, len);
        }

        return 0;
}

int of_alias_get_id(const struct device_node *np, const char *stem)
{
        struct alias_prop *app;
        int id = -ENODEV;

        mutex_lock(&of_mutex);
        list_for_each_entry(app, &aliases_lookup, link) {
                if (strcmp(app->stem, stem) != 0)
                        continue;

                if (np == app->np) {
                        id = app->id;
                        break;
                }
        }
        mutex_unlock(&of_mutex);

        return id;
}

struct device_node *of_get_stdout(void)
{
        return of_stdout;
}